This invention relates to fluid driven pumps and, more particularly, to fluid driven pumps adapted to be driven by a source of fluid pressure which oscillates between a maximum pressure and a minimum pressure.
Existing pumps driven by an oscillating fluid pressure source, such as the crankcase of a two-stroke engine, have limited capacity for pumping fluid.
This results from the pump having a slower discharge rate than the frequency at which pressure oscillations occur in the crankcase. Because the pressure oscilations occur faster than the discharge rate of the pump, the pressure pulse from the pressure source begins to diminish before the pump completes the discharge of fluid. As a result, the amount of fluid which can be delivered by the pump is less than if fluid could be fully discharged by the maximum pressure pulse achieved in the crankcase.
Attention is directed to the pumps disclosed in Leitermann, et al. U.S. Pat. No. 3,765,802, issued Oct. 16, 1973 and Sweet et al. U.S. Pat. No. 2,951,745, issued Sept. 6, 1960.